The invention relates to a vacuum waste-water system sound-absorber and to a sound absorber system to reduce sound in a vacuum system, in particular in order to reduce sound emissions from connected devices (toilet, urinal, galley waste-disposal unit, (GDWU) etc.) to the pipelines of a vacuum system in an aircraft.
Known devices for a vacuum system require the triggering of a flushing procedure after use, by operating a triggering device. Thereafter, flushing fluid is fed to the collection container and subsequently a suction valve is opened in order to feed liquids and other matter to the region of a waste water tank. In this arrangement the transport procedure usually takes place by an airflow, caused by a pressure differential between the waste water tank and the place where the devices are located. During the suction process considerable sound emission occurs in conventional devices as a result of the airflows caused in the suction process.
In industry, sound absorbers are known which however, due to their design size, weight, pressure loss, behaviour during fluctuations in pressure, reliability and service life, must not be used in aviation.